Ron Paul emerged as one of the frontrunners for the Iowa caucus in January, and has flexed his muscle by launching attack ads on his rival Newt Gingrich. As Peter Wallsten reported:

As the first votes in the Republican presidential race approach, Rep. Ron Paul has become a serious force with the potential to upend the nomination fight and remain a factor throughout next year’s general-election campaign.

Although few think the congressman from Texas has a realistic shot at winning the GOP nod, he has built a strong enough base of support that he could be a spoiler — or a kingmaker.

In a muddled field, Paul could win the Iowa caucuses. While other candidates have been hesitant to commit to the state or have had trouble sustaining their initial bursts of support, Paul has been methodically building an organization and a growing corps of followers.

Over the past week, he has spent more than $600,000 on attack ads that are cutting into support for a fellow front-runner, former House speaker Newt Gingrich (Ga.). And Paul has built an organization that will allow him to remain in the race well beyond the early-voting states and amass convention delegates.

Perhaps most fearsome to Republican leaders is Paul’s refusal to rule out a third-party presidential bid that would steal votes from the Republican nominee and make President Obama’s path to reelection considerably easier.

A new Washington Post-ABC News poll, for instance, indicates that Obama and former Massachusetts governor Mitt Romney would be locked in a dead heat in a one-on-one contest. But in a three-way race with Paul, Obama would hold a wide advantage. The survey also suggests that Paul on his own would pose at least as much danger to Obama as Gingrich would.

“The reality is Ron Paul is poised to become a major figure in the Republican Party if his momentum continues and he’s able to win in Iowa,” said GOP strategist Steve Schmidt, who managed the campaign of Sen. John McCain (Ariz.), the party’s 2008 nominee. “The open question is: How much durability does he have over the balance of the race?”

For many analysts, the chances of Ron Paul’s nomination as the GOP candidate for president are still slim. As Aaron Blake explained:

Rep. Ron Paul (R-Texas) has expanded his political brand enough to potentially win the Iowa caucuses in two weeks.

While Paul seems to have taken advantage of a good situation in the Hawkeye State and has improved his position nationally as well, his brand of politics remains wholly unpalatable to vast swaths of the GOP.

Paul has long been seen as a phenomenon relegated to a small slice — 5 or 10 percent — of the Republican Party. But during the 2012 campaign, he has slowly built his brand and turned himself into something more than just a favorite of libertarian-leaning Republicans (as the Post’s Peter Wallsten writes).

And he appears to have even more room to grow — to an extent.

The Post/ABC poll shows he is the first choice of 15 percent of voters, which is good for third place. But perhaps more interestingly, he is the second choice of 12 percent of respondents. That means more than a quarter of Republicans can see themselves voting for Paul right now — a number that would have seemed impossible at the start of the campaign.

But once you get beyond that quarter-plus, the opposition hardens significantly.

For an example, look at his position on foreign policy.

The new Post/ABC poll finds that 45 percent of Republicans and Republican leaners say that Paul’s opposition to U.S. military intervention overseas is a “major reason” to oppose he candidacy.

By comparison, only 36 percent say that same of the health care bill Mitt Romney signed as governor of Massachusetts. That bill is supposed by some to be Romney’s albatross and has been covered much more in-depth during the presidential campaign. Yet Paul’s foreign policy is much more of a hurdle for him.

Among self-described conservatives, it’s an even bigger hurdle: 56 percent say Paul’s foreign policy is a major problem, while just 41 percent say that same of Romney’s health care bill.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.

To pause and restart automatic updates, click "Live" or "Paused". If paused, you'll be notified of the number of additional comments that have come in.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.